Atlas of Relations Between Climatic Parameters and Distributions of Important Trees and Shrubs in North America

The Atlas of Relations Between Climatic Parameters and Distributions of Important Trees and Shrubs in North America explores the continental-scale relations between the geographic ranges of woody plant species and climate in North America. On the continental scale, climate is the primary determinant for the overall geographic ranges of plant species (Woodward, 1987; Woodward and Williams, 1987). Geologic studies reveal that the geographic locations and extents of plant species have changed greatly as climate has varied in the past (e.g., Huntley and Webb, 1988; Wright and others, 1993). In the Atlas, the climatic parameters that may likely control the modern distributions of selected plant taxa for North America are investigated.

For the Atlas, a 25-km equal-area grid of modern climatic and bioclimatic parameters was constructed from instrumental weather records. The geographic distributions of selected tree and shrub species were digitized, and the presence or absence of each species was determined for each cell on the 25-km grid, thus providing a basis for comparing climatic data and species' distributions. The relations between climate and plant distributions are explored in graphical and tabular form.

The Atlas presents information on the modern relations between climate and the distributions of 407 plant taxa and biogeographic entities from across North America. Included among these are 115 conifer species, 32 conifer groups (such as the genera and subgenera), 239 hardwood species, and 21 hardwood groups.

The results of this effort are primarily intended for use in biogeographic, paleoclimatic, and global-change research. For example, these data may be used in the reconstruction of past climates from paleoecological data, in the estimation of the potential future ranges of important trees and shrubs under various global-change scenarios (such as those depicted by Houghton and others, 1996, and Thompson and others, 1998), and in validation exercises that compare past plant distributions with those simulated based on numerical-climate-model simulations of past climates (Bartlein and others, 1998). This information may also be useful in a variety of ecological and biogeographic studies, particularly in generating hypotheses for testing.

The Atlas web site provides access to the text, digital representations of figures, and supplemental data files from USGS Professional Paper 1650, Chapters A and B (See Citation). A printed set of these volumes can be ordered from the USGS at a cost of US$63.00. To order, please call or write:

USGS Information Services
Box 25286
Denver Federal Center
Denver, CO 80225 USA
Tel: [phone]; Fax: [phone]